The ordeal started Thursday at dusk when the victim -- only identified as a Solano County resident -- was kidnapped at gunpoint in the parking lot of Gateway Plaza shopping center in Vallejo, police Lt. Jim O'Connell said. It was unclear if the woman was a shopper or store employee.

O'Connell said the woman is recovering at a local hospital.

King allegedly forced the woman to drive from the shopping center to a location several miles away where she was sexually assaulted, beaten and left unconscious and duct-taped in a ditch near Hiddenbrooke Parkway and Interstate 80.

At about 6 p.m., police were alerted by passers-by who had spotted the woman and tried to help her. O'Connell said the passers-by also provided police information that eventually led to King's arrest.

O'Connell said while detectives were developing leads, a family member of the victim was contacted by phone and the caller demanded an unspecified amount of money in exchange for the woman's return.

Police returned to the scene of the alleged abduction, and later found King there with the vehicle, some of the woman's property and in possession of a replica handgun. King was arrested without incident and later booked into Solano County Juvenile Hall on charges of assault, attempted murder, carjacking, armed robbery and kidnapping for ransom.

At a news conference, O'Connell said there was no known relationship between the victim and assailant.

"This appears to be a random attack," O'Connell said. He would not give further details or say whether King had made any statements to police.

"The last thing we want to do is jeopardize any prosecution," O'Connell said. "But we did have a conversation with the victim. She is an incredibly strong, insightful woman ... but as for any other details ... I don't want to share that at this point."

The victim was still recovering Friday morning at an area hospital. O'Connell would not give details about her injuries, but said they were "serious." She is expected to survive.

O'Connell told reporters the passers-by played an integral role in helping the victim.

"They were tremendously helpful ... they got her aid ... I think it could have had a different result if they hadn't helped her," he said. "I think they are great citizens and I appreciate what they did."

Asked if police believe the attack was premeditated, O'Connell said: "We don't really have any thoughts on that at this point that we want to share. Obviously, most people don't walk around with duct tape ... but as for any other elements of that ... we want to hold on that.

"There is not usually such a wide gap in age between victims and suspects," O'Connell added. "Any age is the wrong age to do something like this. But we certainly don't expect most 14-year-olds to do something of that nature."

Police said the abduction occurred about an hour to an hour and half before the victim was found. The suspect was arrested a few hours later after he had returned to the same parking lot, near Toys R Us. Police would not comment on why he returned to the area.

Police said the family reported the ransom demand, but details of the call have not been released. No ransom was paid.

"He came back around," O'Connell said, "and detectives observed him, recognized him and took him into custody."